net.cnri.dobj.edo

Class EDOOperator

java.lang.Object

net.cnri.dobj.edo.EDOOperator

public abstract class EDOOperator
extends java.lang.Object

Interface for dynamically loaded digital object "operators". Each operator instance extends

Constructor Summary

Constructors

Constructor and Description
EDOOperator()

Method Summary

Methods

Modifier and Type	Method and Description
abstract boolean	canHandleOperation(EDOOperationContext context) Returns true iff this object can perform the given operation on behalf of the caller on the given object.
abstract java.lang.String[]	listOperationIDs(EDOOperationContext context) Returns a list of operations that this operator can perform on the object identified by the DOOperationContext parameter.
abstract void	performOperation(EDOOperationContext context, java.io.InputStream in, java.io.OutputStream out) Performs the given operation (which this object has advertised that it can handle) which consists of reading input (if any is expected) from the given InputStream and writing the output of the operation (if any) to the OutputStream.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

EDOOperator

public EDOOperator()

Method Detail

canHandleOperation

public abstract boolean canHandleOperation(EDOOperationContext context)

Returns true iff this object can perform the given operation on behalf of the caller on the given object. The operation, object, caller, and request parameters are all provided by the given DOOperationContext object.

listOperationIDs

public abstract java.lang.String[] listOperationIDs(EDOOperationContext context)

Returns a list of operations that this operator can perform on the object identified by the DOOperationContext parameter.

performOperation

public abstract void performOperation(EDOOperationContext context,
                    java.io.InputStream in,
                    java.io.OutputStream out)

Performs the given operation (which this object has advertised that it can handle) which consists of reading input (if any is expected) from the given InputStream and writing the output of the operation (if any) to the OutputStream. This method should always close the input and output streams when finished with them. If there are any errors in the input, the error message must be communicated on the OutputStream since all errors must be at the application level. Any exceptions thrown by this method will *not* be communicated to the caller and are therefore not acceptable.